They are pretty inexpensive and sentimental as well. Even put on a necklace they would be cute as well. Also Two Roads Fitness has a section of just running jewelery that include some already made necklaces at great prices as well. Wearing a necklace that reminds you daily what your goal is, or what you've accomplished is a great way to remember your hard work and training. Also by giving this gift to a runner, it shows that you recognize their accomplishments.
Here are some more charming links :
Finish line charms - Really cute and really different looking charms. Key chains, necklaces and even ornaments!
Crafting and Jewelery - Custom Marathon -Personalized and unique
Zulumoon - Running Charms - Really cute shoes charms
My Triathlon Jewelry - Really cute pendants and a super cute I heart running key chain seen below
Glad you all seem to be enjoying the list thus far. Don't worry I have many more random and great tricks up my sleeve. Tonight I'm going for a little jog to keep loose for the race this weekend... Gotta keep the mileage up even in the dark!